IJPEM

Design and Manufacture of High Accurate Aerostatic Guideway with Glass Material

Xiaoqiang Peng/National University of Defense Technology, China

KEYWORDS: Glass material, Aerostatic guideway, Orifice compensated, Geometric error, Optical manufacture and measurement

Universal materials such as metal and marble are applied for aerostatic guideway. However, metal or marble guideway is usually manufactured by traditional turning and grinding. The corresponding geometric error, load and stiffness of the guideway are limited by the accuracy of traditional manufacture. Glass guideway can be measured by the optical method, thereby improving the performance. This paper presents a guideway designed and manufactured with the K9 glass. The guideway is manufactured by computer controlled optical surfacing and magnetorheological finishing. Moreover, the optical measurement is applied to measure the flatness and the geometric error of the guideway. Besides, the slider on the guideway is designed based on orifice compensated. The working surface error of the guideway is less than 0.1 μm, and the gas film is smaller than traditional aerostatic bearing. Therefore, the load and stiffness of the aerostatic sliders are higher than the traditional slider. Additionally, the effects of configuration and load onto the accuracy of guideway are introduced. The motional geometric error is measured after assembling, with the results that the pitch is better than 0.4 arcsecs and the yaw is better than 0.9 arcsecs. Furthermore, the straightness is compensated at 50 nm/200 mm. At last, the guideway is applied for an ultra-precision profilometer, and a flat is measured by the profilometer, giving 0.1 μm repeatable flatness.